CODEWITHSUNDEEP
c++opencvmatrix
user3652562
user3652562

Reputation: 33

Opencv << operator error for cout and writing to FileStorage

I am having problems getting the << operator to work for cout and writing to a FileStorage object in Visual studio c++ 2010 express. I am using the vs10 libraries, included the ***d.lib files and am running my project in debug mode. Other opencv functions (ORB, imshow) seem to work

When I use the << operator for printing a matrix with cout I get an access violation error.

The second issue I am having is when I try to write a matrix to a FileStorage object. I can write 1 matrix and read it from the file without it crashing. When I however try to write 2 matrices I get an "Exception at memory location" error on the second write. The console error says that No element name has been given.

The code I used for testing:

cv::Mat test(3,3,CV_8UC1);
cv::FileStorage file("fudge.xml", cv::FileStorage::WRITE);  

for(int x=0;x<3;x++){
    for(int y=0;y<3;y++){
        test.at<unsigned char>(x,y) = x+y;
    }
}

std::cout<<test<<std::endl;

file << "rotMat1" << test;
file << "rotMat2" << test;

Code Update

this is my entire code 

#include "stdafx.h"
#include <opencv2\core\core.hpp>
#include <iostream>

int _tmain(int argc, _TCHAR* argv[])
{
    cv::Mat test(3,3,CV_8UC1);
    cv::Mat test2(3,3,CV_8UC1);

    cv::FileStorage file("fudge.xml", cv::FileStorage::WRITE);  

    for(int x=0;x<3;x++){
        for(int y=0;y<3;y++){
            test.at<unsigned char>(x,y) = x+y;
            test2.at<unsigned char>(2-x,2-y) = x+y;
        }
    }

    std::cout<<test<<std::endl; //error 1

    file << "AAAAA" << test;
    file << "BBBBB" << test2; //error 2

    return 0;
}

both errors still occur

UPDATE, I fixed it (kind of)

I found the problem but now there is a new one. So the problem was that because I have projects in both VS2010 and VS2012. Because of this I added both vs10/bin and vs11/bin to the path variables. It turns out that this results in visual studio using vs11/bin (maybe because that was declared first). After removing the vs11/bin decleration it worked in vs2010 but now vs2012 is broken. Because this isn't part of the original problem I will set it as answered.

Upvotes: 1

Views: 1866

Answers (3)

user3652562
user3652562

Reputation: 33

The problem was that because I have projects using opencv in both visual studio 2010 and 2012 I added both /dir paths to the environment path variable. This resulted in visual studio always using the 2012/dir (probably because this was declared first). After removing the 2012/dir it worked fine.

Upvotes: 1

The Nomadic Coder
The Nomadic Coder

Reputation: 650

I don't think the namespace is the problem. Two things that I could think off that cause the problem:-

  • did you release your file object?
  • In the XML file, both your entries would have the same field. I'm not sure if this is supported by XML filestorage in Opencv. Did you try writing twice with different Mat objects?

Upvotes: 0

user1990
user1990

Reputation: 546

you need to add using namespace cv;

follow this exemple : http://docs.opencv.org/modules/core/doc/xml_yaml_persistence.html#xml-yaml-file-storages-writing-to-a-file-storage

Upvotes: 0

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